Tsup 8.1.0 introduces notable updates for TypeScript library bundling, building upon the solid foundation of version 8.0.2. A key highlight is the upgrade of its core bundler, esbuild, from version 0.19.2 to 0.21.4. This enhancement promises improved build performance and potentially better compatibility with newer JavaScript and TypeScript features. While most dependencies and devDependencies remain consistent, this core upgrade often translates to faster build times and more efficient code output, directly impacting developer productivity.
The peer dependencies remain consistent between the two versions, ensuring compatibility of tsup with other tools like PostCSS, SWC, and TypeScript, but developers using tsup in larger ecosystems should continue to ensure their tooling adheres to these peer dependencies.
Tsup continues to offer a zero-config approach, simplifying the bundling process for TypeScript libraries. Developers will appreciate the straightforward setup, as Tsup handles the complexities of bundling, allowing them to focus on writing their code. The tool is designed for efficient library creation, seamlessly integrating with existing workflows. Tsup remains an excellent choice for developers seeking a fast, configuration-free bundler for their TypeScript projects. The jump to esbuild 0.21.4 should be the main focus when considering the upgrade to the latest version.
All the vulnerabilities related to the version 8.1.0 of the package
tsup DOM Clobbering vulnerability
A DOM Clobbering vulnerability in tsup v8.3.4 allows attackers to execute arbitrary code via a crafted script in the import.meta.url to document.currentScript in cjs_shims.js components
esbuild enables any website to send any requests to the development server and read the response
esbuild allows any websites to send any request to the development server and read the response due to default CORS settings.
esbuild sets Access-Control-Allow-Origin: * header to all requests, including the SSE connection, which allows any websites to send any request to the development server and read the response.
https://github.com/evanw/esbuild/blob/df815ac27b84f8b34374c9182a93c94718f8a630/pkg/api/serve_other.go#L121 https://github.com/evanw/esbuild/blob/df815ac27b84f8b34374c9182a93c94718f8a630/pkg/api/serve_other.go#L363
Attack scenario:
http://malicious.example.com).fetch('http://127.0.0.1:8000/main.js') request by JS in that malicious web page. This request is normally blocked by same-origin policy, but that's not the case for the reasons above.http://127.0.0.1:8000/main.js.In this scenario, I assumed that the attacker knows the URL of the bundle output file name. But the attacker can also get that information by
/index.html: normally you have a script tag here/assets: it's common to have a assets directory when you have JS files and CSS files in a different directory and the directory listing feature tells the attacker the list of files/esbuild SSE endpoint: the SSE endpoint sends the URL path of the changed files when the file is changed (new EventSource('/esbuild').addEventListener('change', e => console.log(e.type, e.data)))The scenario above fetches the compiled content, but if the victim has the source map option enabled, the attacker can also get the non-compiled content by fetching the source map file.
npm inpm run watchfetch('http://127.0.0.1:8000/app.js').then(r => r.text()).then(content => console.log(content)) in a different website's dev tools.Users using the serve feature may get the source code stolen by malicious websites.